Automatic telephone-exchange for double-wire telephone systems.



No. 839,095 -'PATENTE'D DEG; 25,1906.

I 4 G A.'BETULA'NDER I AUTOMATIC TELBPYHONEIEXIOHYAN-GE FOR DOUBLE WIE TELEPHONE SYSTEMS. E E

urngouion'riLEnmm. 9. 1903.

2 SHEETS-SHEET 1.

6" g "a EINVENTOR ATTORN F PATENTED DEC. 25, 1906. G. ASBETULANDER.

AUTOMATIC TELEPHONE EXCHANGE FOR DOUBLE WIRE TELEPHONE SYSTEMS.

APPLiCATION FILED MARPQ, 1903.

v SHEETS-SHEET 2.

A I Q a wi/tyieweo fij d ww/koz U NITED STATES PATENT OFFICE. oTTHILF ariseAait s BETULANDER. or sTocKHoLM. SWEDEN.

AUTOMATICTELEPHONE-EXCHANGE FOR DOUBLE-WZIRE TELEPHONE sYsigMs.

No, 889,095. I

To alt'w hom it may concern; a f

' Be it known that I, GOTTHILF Ansoanrus BETULANDER, a subject of the King of Sweden, anda resident ofStockholm, in the.

Kingdom of Sweden, have invented certain new and useful Improvements in Automatic Telephone-Exchanges for Double-Wire Telephone Systems, of which the following is a specification, reference being had therein to t e accompanying drawings. I

. This invention relates to automatic tele phone-exchanges for double-wire telephone systems of that kind where an earth (301111613? tion is employed at the exchange durin all the time used in automatically .establis ling telephonic conununication between fltele-f phone systems, the arrangement comprises a connecting apfiaratusplaced at the automatic f line branch and the disconnection b' one ,in-'

'telephone-exc ratu's placedat theisubstation. The con-nections .are such that the desired connection of one substation with any other isperformed by successive. interruptions or breaks in' one terruption-or break'in the other line ranch.

The drawinfgs Figure 1 and F' 1". show a diagram o an automatic 'te ephone-excha ge systemarranged accordingto this in v i m "The diagrams Fig's. l 'and 1 comprise four telephone apparatus 1, II, III, and IV, each connected bydouble wires with a connecting e telephone-exchange. The arrangement is suchthat "at every substation each line branch 1 and2 before entering the telephone apparatus includes a switch or circuitbreaker3 .4,-contacts' 5 6 being provided for connecting the said switches with the earth when required. One switch 3, hereinafter called the connecting-switch, is used for establishing the "desired connections and the other switch 4, hereinaftercalled the disconnecting-switch, for disconnection. One of the earth-contacts 5 and 6 may be dispensed with, in which case the corresponding line branch is-connected' with the earth through the telephone apparatus or through a conductor forrnin a short circuit about the said apparatus. referably automatic controlling apparatus nausea at the.

Specification of Letters Patent; Application filed much 9,1903. Serial No. 146.804.

ange and a controlling appa- .nected in .circuited t rough same.

apparatus A, B, O, and D, respectively, atcontact-spring CS pressed down. 1

however, the telephone-receiver is'removed Patented. Dec. 25, 1906.

' substations, said apparatus being construct ed and arranged in such a manner that in order to establish a desired connection'the con-' trolling apparatus first closes one of the earth contacts 5. and'6 at'the substation, then alternately breaks and makes the connectingswitch, and, finally, breaks the earth contafcts 5 6 before the last closing of the said switch. The telephone apparatus is then connected with the desired substation- In disconnecting, thdcontrdlling apparatus at the substation first closes one of the earth contacts 5 6, then breaks the disconnectingswitch4,-then breaks the earth contacts 5 6, and, finally, closes the disconnecting-switch 4. The specific form of automatic control ling apparatuspreferred is not essential and does not form any subject of the resentinvention, and the switchesand eart contacts are therefore .shown mer ely diagrammatic- The arran ement-atthe substation may be as follows: I 'orrnall y ('8. e,., when th'e -te1ehone-receiver TR is hanging upon its hook T1) the followingparts are'bridged between the line'branches I and 2,.switch 3, magnetogenerator MG, signal-bell SB, switch-hook -H, lower contact-anvil LC, and switchf4.

The secondary winding SW of the inductioncoil'an'd thetelephone-receiver TR are conarallel with hook H and short- The primary circuit, comprising the microphone-battery'MB, the micro hone M, the prlmary winding PW of the in uction-coil, the contact-spring CS, and the contact 0, is now broken, since the insulating piece I- at the hook H kee s'the from itsswitch-hook, the latteris pressed by its springagainst the upper contact UC, by

"which themagnetoenerator MG and" the signal b'ell 8B are s ort-circuited {through the hook H, whereas the secondary winding SW of the induction-coil and the telephone.- receiver TR are bridged betweenthe line branches land 2. At the same time theprimary circuit is closed through the contact-spring CS and contact-piece C. The

described arrangement at the substation is not essential, as it'will be understood that it parting from the spirit and scope of this invention. p The connecting apparatus connected with Ice {can be modified in various ways without dethe subscribers'telephone apparatus comprises a connecting-electrolnagnet 9, a dis- I connecting-electroinagnet 10, a locking-electroinagnet 11, whose armature 33 normally prevents the armature 22 of the connectingelectromagnet from being attracted by the latter, and a cut-out electroinagnet JZ, serving to prevent the connecting-springs during the connection operation from making contact with connecting-wires leading to the connecting apparatus of subscribers with which no connection is desired. Of the two line branches 1 2 the one, 1, is connected with the connecting electroinagnet 9, as also through a wire 13, with one of the connecting springs 15, and the other line branch 2 is connected with the disconnecting-electromagnet 10, as also through a wire 14, with the other connecting-spring 16. The Windings of the connecting and disconnecting electromagnets are connected together by a wire 17 and each of the said windings is, further, connect Pd by a ire 18 19 with a contact 2021, as shown in the drawings. The armatnres 22 .23 of the electromagnets- 9-10 are elec-' 2 trically connected togther by awire 24 and, further, connected throughthe windings of the locking and cut-outelectromagnets 11 12 and wires 25 26 with'one pole of the, connecting battery 27, the other pole of which is connected with the earth.

. The armature 22 of the connecting-electromagnet 9 is provided with a feedin -pawl 28 or. the like, on aging the notches o a bar 29 or other mova le part carrying the connect ing springs 16, connected with the 'line branches 1 2. The movable part 29 is adapted to slide up and down, but not to be turned. The armature '23 of the disconnecting-elec tromagnet lOcarries a locking-pawl .30, that. when the disconnecting-electromagnet is energized and keeps-its armature 23 attracted engages the notches of themovable'part 29 to prevent its falling down. When the our I rent ceases to flow through the electromag- 45 nets 9 10, the armatures 22 23 are, retracted by their springs 31- 32 in the positions shown in the drawings. 1 Suppose the subscriber at substation III 3 wishes to put himself in communication with substation IV. He thencloses one of the earth contacts 5 6 at'his telephone apparatus III and rotates the armature of the g magne'to generator of said apparatus. Both contacts 5 and 6 must not be closed simultaneously,-si-nce the current from the magnetogenerator Would .then be short-'circuited I through the earth contacts, and thus would not energize the electroniagnets 9, and 10. It does not matter, however, if contact 5 or contact 6 be closed. If, for instance,contact .5 be closed, the current from battery 27 after the electrornagnets 9 10 having been excited by the magneto-generator current and --the electromagnet 10 having attracted its arrna tus.

6 5. 't'ure 23, the ar1natu-re22. of the electromagries, wire 24, armature 23, (which is attracted against its contact 21,) contact 21, and wire 19, from whence itdivides, one path being through wire 17, electromagnet 9, line branch 1, and contact 5, the other path being through electromagnet 10, line branch 2, tel.

ephone apparatus of the calling subscriber, and contact 5 to earth, and from thence back to battery 27. Interposed between the armature of the contacts 5 and 6 at one side and theearth at the other side is an electromagnet E, that is excited by. the battery-current and attracts its armature, which then closes contact 6. In case'contact 6 be closed instead of contact 5' the battery-current would flow from battery 27 through electromagnets 12 and 11 in series, wire 24, armature 23, (which is attracted against its contact' 21,) contact 21, and wire -19, from whence it dividesfone path being through the disconnectingelectroniagnet 1-0, line branch 2, and contact 6,-the other path being through wire 17, eonnecting-electromagnet 9, line branch 1, subscribers telephone apparatus, and contact 6 to earth and from thence back to battery 27. The electronragnet E when energized by the battery-current attracts its arrr' ature and in this instance-closes contact 5. It will thus be found that only one (5 or-6) of the earth contacts isclosed-by hand, the other one being automatically closed after the magneto-gcnorator -crank has loo been rotated by the current from battery 27.

The object of the closing of the other earth contactis n'erely to short-circuit the magnote-generator current through earth immediately after the contact 21 has been closed, lo 5 the only purpose of the magneto-generator current being to close the said contact'21, so that the movable part 29 cannot be unintentionally fedforward b the aragnetogenerm tor current, alternate y increasing and de- 1 1o creasing thecurrent from battery 27 through the connecting-electromagnet 9. The rotating of the arir. ature ofthe magnetogenerator at a substation after one of ,the earth contacts 5 6 has been closed-causesan alter-nae r I;-

ing current to pass through the telephone apparatus III, one line branch-.1 ,electrom agnet 9, wire 17, electromagnet-10, and the-other line branch 2 back to the telephone appara- The electromagnet 10 then attracts its arlr. ature 23,thereby establishing the following circuit: earth, 'battery27, wire 26, wire 25 of connecting apparatus C, electminagnets 12 and '11 in'series, wire 24, armature 23, con-' tact 21, .wire' 19, from which the circuit -divides into two branches, one comprising the wire 17, electromagnet 9, line branch 1, switch 3, 'contactfi,v and ear-eh. the other comprising the electromagnet 10, line 2, switch 4', contact 6, and earth. The electroinagnet 11 being energized attracts its armature 33, thus releasing the armature 22, which is now attracted by its electromagnet 9. The

' current from battery 27 then after having passed the electromagn'et 11 divides. in two branches, one comprising the armature 22, contact 20,'wire 18, electromagnet 9, line 1, and earth, the other comprising the armature 23, contact 21, wire 19, electro'magnet 10, line 2, and earth, the electromagnets 9 and 10 thus continuing holding their arinatures in attracted positions. On account of the electro'lnagnets 9 10 having attracted their an matures the feeding-pawl 28 has passed the uppermost tooth of the bar 29 and entered into the notch beneath the said tooth, while ,;the pawl- -engages and aids in keeping the of thebar 29 in position. The lower en feeding-pawl has nowpassed the upper end ofthe arn'iature 23, whose upper end has entered between the bar 29 and the feeding pawl. Tf the connecting-switch 3 at substation III is now broken, the current from battery 27 ceases to flow through the electrowires. When the bar 29 is raised, the end of magnet 9, and the armature 22 with its feed ing-pawl 28 are retracted by the spring 31, the tension of which is so adjusted that the pawl 28 raises the bar '29 a distance corresponding to the length of! a tooth which is equal to the distance between the connectingthe pawl 30 slips over a tooth at the bar and enters the notch nearest below that tooth, thus holding the bar in its raised position in case the connecting-switch 3 should again close the circuit through the electroinagnet 9,.

It follows froin the preceding that if it be desired to raise the bar 29 say four teeth four interruptions are to be made with the switch 3, the earth contacts 5 6 being broken before the switch 3 is allowed to return and make contact after the fourthinterruption. On account of the break at the earth contacts 5 6 the batte'ry27 ceas'esto supply current to the electromagnets and the armature 23, with its pawl 30, is retracted by the spring 32, so thatthe pawl 30 is brought out of env has been finished, to restore the connecting gagement with the bar 29, which is now kept in its raised position onl by the pawl 28.

When it is desired, a ter the conversation apparatus to its normal or resting position,

this is performed by closing one of the earth contacts 5 6, rotating the rnagnetogenerator MG, breaking the disconnecting-switch 4,

breakin the earth contacts 5 and 6, and allowingt e disconnecting-switch to return in its closing position. By closing one of the contacts at 5 6 and rotating the magneto-generator of the telephone apparatus the electroma nets 9 and 10 are caused, as before describe to attract their armatures 22 23, re-

spectively, and the lower end of the pawl 28 en, as before, passes theupper end-0f the armature 23'. By breaking the switch 4 an interruption is rnade in that branch of the circuit of battery 27 comprising the electromagnet 10, and the armature 23 is thus reend of the armature 23 pro'ects between the bar 29 and the pawl 28 the iatter is caused to follow, so that the saidpawl is withdrawn from engagement with the 'bar, which is brought back'b'y its own weight or by any other force into its normal position. Before the switch 4 is allowed to return and make contact the contacts 5 6 are broken, whereby the branch of the'circuit of battery 27, comprising the electrornagnet 9, is also broken. The armature 22 is then retracted 'by its tracte'd by its spring 32; but as the upper 1 spring 31 and pulls the pawl '28 upward, and

when the upper end, of the armature 23 re-- leases the end ofpawl 28 the latter enters, into and engages the uppermost notch in the bar 29,

fiedfby connecting the battery 27 throu h the electromagnets 12 and 11 directly wit the electromagnets 9 and 10. This modification of the connection is shown at the connectin a paratus D, Where the wires 18 and 19 and t t ie contacts 20 and 21 have been substituted by a wire 34, connecting wire 24 with wire 17';

The described arrangements can be, modi- In this casethe subscriberat substation IV for establishing a desired connection or. for disconnecting need not send current from the magneto-generator through the line, because when one ofthe contacts 5 6 is closed a cir-' cuit for the battery 27 is established through the earth, battery 27 wires 26 and 25, electromagnets 12 and 11 in series, wire 24,-wi1'e ICC 34, wire 17, and in parallel through the electroinagnets 9 and 10. and the line branches and 2 back to the earth.

If the battery 27 is not permanently con-. nected With'the electromagnets 9 and" 10, arrangernents should be provided to enable any subscriber to break his connection with another subscriber in case the lines of the latter have accidentally been short-circuited. To

this end resistances 35 -36 are interposed in the conductors between the subscribers, suitably in the conductors 13 and 14, leading to ances allowing a suiiiciently strong current to pass from the magneto-generator at the subscribers telephone apparatus through the.

the connecting-springs 15 and 16, said resistthese wires.

actuated. when the subscriber, after having established. the desired connection, rotates the magnetoenerator of his'telephone ap aratus to pro uce a calling-signal. On t is 5'occasion the contacts 5 6 are open, so that although the armature 23 is attracted by its electromagnet 10 and the contact 21 is closed 5 have'to pass'before they reach the wire of the.

I To this endtthe electroe magnet 12;.is placed at the upper end of the desired subscriber.

- bar29 and provided with an armature 37,

- carryingthe insulated contact-sprin s 16. 20. As the raising of the bar 29 can ta e place only during the time the armature 33 of the locking-electromagnet 11 isattracted, and

as the current from battery 27 through the electromagnet 11' hasto first pass the cut-out electromagnet v12, it is obvious that on a'ccount of the attraction of the armature 37 by its electromagnet 12 the contact-springs 15 16 are kept away from the wires 101 102 103, &c., and 111 112 113, &c., respectively,

0 when passing the said wires. Further, inasmuch as the contacts5 6 at the telephone apparatus are kept closed, and thus the electromagnet 12 is sup lied with current from the ,battery 27 only uring the time necessary to 3 5 establish the desired connection, the contactsprings 1516 arekept in elevated positions only while being broughtoppos'ite the contact-wires of the desired subscriber, after which they are allowed to make contact, with The connecting apparatus -'is,' further, arranged in such a'manner that while-a conversation between two subscribers'takes .plaee any third subscriber'is debarred from dis- 4 5 turbing or' overbearing the conversation.

; For this purpose an insulated spring 38 is attached to the armature 37- of the electromagnet '12, said spring having such a position as to make'contact with one after the other of a 5o number of wires 121 122 123, 850., each be longingto one of the connecting apparatus AB C D, &c. a The spring 38 can suitably be provided at its free end with a small wheel 39, rolling during the rising of the bar 29 on the wires 121122 123, It should beehserved that as soon as the bar 29 has been raised from its position'of repose the spring 38 is always-in contact'wit'h one of the wires -121"122.123,&*c., (thusalso during. the conj 66 nection operation when the armature 37. is v 1, attracted byits electromagnet.)

' 38' has an extension 40, that is in contact The spring with'one ortheother of two contacts 41 42, according as the armature 37 is at rest or attr'acted, one of said contacts 41 being con-' &c.

with substation IV. During the raising of 'nected by the wires 43 and 44 with one pole of a battery 45, whose other pole is connected through the wires 26 and 25, electromagnet 12, and wire 48 with the other contact 42., Placed upon the connecting apparatus are, further, two springs 49 50, one of which, 49, is connected through wires 51 and 44 with the battery 45 and the other, 50, through a wire 52 with one of the wires 121 122 123,

The bar 29 further carries a knob 53 or 7 5 the like, of insulating material, said knob having such a position that when the bar 29 ta es up its lowest position (see apparatus D) thesprings 49 50 are kept apart by the knob 53, whereas when the bar 29 is raised the knob 53 leaves the spring 50 and allows the latter to make contact with the spring 49.

- In order to be clearly understood 1n what manner a third subscriber is debarredfrom disturbing or overbearing a conversation between two other subscribers, it may be en posed, as before, that the subscriber at su station III has put himself in connection with substation IV. The metallic circuit established between the substations III and 0 IV is then formed by the telephone apparatus III, switch 3, line 1, wire 13, spring 15,

wire 104, spring 15 at the apparatus D, wire 13, line 1, switch 3, telephone apparatus IV, 4 switch,4,line 2, Wire 14, spring 16, .wire114, spring 16 of the apparatus C, wire 14, line 2, and switch 4 back to the telephone apparatus III. Nowsuppose thesubscrlberatsubstation II desires to put himself in communication the bar 29 of the apparatus B the electromagnet 12 keeps its armature-37 attracted, so that the extension 40 of spring 38 bears u on the contact 42, as shown at B. When t e bar .29 has reached its desired osition, the armature 37 at the apparatus I in case the apparatus IV were not-busied, would be released by the electromagnet and return to its normal osition, whereby the springs 15 and 16 won d come irr contact with their contact-wires 104 and 114,- z'espectively. .Now this is not the case, because a circuit. is closed for the batt'ery 45 through wire 26, wire 25 at the apparatus B, electromagnet'12,'wire 48, contact 42, spring 40 38, contact-wheel 39, wire 124, contactwheel. 39 at theapparatus 0, spring 38 40, contact 41, and wires 43 and 44 to the other pole of the battery 45. The electromagnet 12 of the apparatus B is,

therefore, still supplied with cur nt, but' now 1 20 from battery 45, which supplies the electromagnet with current in the same direction as before from the battery 27. The subscriber at substation II cannot,-therefore, disturb the conversation between the subscribers at substationsIII and IV by an attemptto put himself in communication with substation TV. If, on the other hand, he tries to put himself in communication with substatlon III, a circuit is closed from battery 45 1 esaoes through Wire 26, wire at theapparatus B,

electromagnet 12, Wire 48, contact 42, spring 38, contact-wheel 39, wire 123, wire 52 at the electromagnet 12' partly through wires 44 i and 43,; contact 41, and spring 40 38 with a cut-out wire 124, entering the co'nnectingapparatus D of the desired substation IV, and partly through wire 44, wire 51, springs49 50,

and wire 52 with the cut-out wire 123 of-the: connecting apparatus that establishes 'the connection, thus preventing ,all other sub .scribersfrom connecting themselves with any of the two substations IIIv and IV con-- nected together for conversation, Fu'rther arrangements are provided to'enable the -op-: erator at the long-line station I or the connecting a paratus Act the long line to interrupt loca conversations-within the range, of the automatic exchange and to connecti'itself' with any of the substations either busied or not For this urpose the connecting-wires 102 103 104, c., and 112 113.114, 800., do not-enter the connecting apparatus A, but are there substituted'by-other wires 132133 134, &c., and 142143 144, &c., respectively,

.two of these wires 132 and 142, one of each series, being connectedwith contacts and v 56, respectively, at the connectingapparatus B; two other wires-133 and 143, one of each series, with contacts 55 and 56, respectively,- atthe connecting apparatus 0, and'so on.

' Each pair ofcontacts 55 56 is connected,

throu h springs 57 58, wires 59 60, and wires .13 an 14,,withthe lines 1 and 2 of the cor- 5 responding substation. Also the cut-out wires 122-123, &c.,- do not enter'the connecting apparatus A of the long-distance line, but are -substituted at this apparatus'by wires 152 153,. 020., each connected insuch a manner with the cut-out electroniagnet 12 of one of the other connecting apparatus that the cutout electromagnet 12 corresponding to the substation with which the long-distance line has been connected is energized by current 'from the cut-out battery 45. If the substations III and 'IV'are' connected together for I the connecting a paratus A with substation IV, a current wil flowfrom battery .45 through wire .26, wire 2-5 at the connecting apparatus" D, electromagnet, 1-2,.'

wire 154,contact-wheel 39 at the connecting apparatus A, spring 38 40, contact 41, wire 43,- and wire44 back to the cut-out battery.

, 45. The armature 37 of the cut-out electrobetween. substations bro'ken,{tl1e springs 15 16 at the cmmbflm g" Bgnet 12 -at the 'connecting'apparatufl D will thus be attracted, wherelg the metallic I and IV .15

c connection. between the and partly apparatus vD being lifted away from the wires 104 and 114-. A complete rnetallic circuit is established between substations. I and IV through the telephone apparatus I, switch 3, hne' 1, wire 13, spring 15, wire 134, contact 55 at the connecting apparatus D', contact spring 57, wire 59, wire 13, line 1, switch 3, I I

telephone apparatus IV, switch 4, line 2, wire 14, wire 60, contact-spring 58, contact 56, wire 144, spring 16 at the connecting a paratus A, wire 14, line 2, and switch 4 bac to the telephone apparatus I. At-the connecting a paratus A the contact-whee139, carried by I t e sprmg 38, is not allowed during the connecting operation, while the armature 37 is attracted to make contact with any of the wires 1'52 153, &c., (-in opposition to the case in the'other connecting apparatus B C, &c.) Further, each connecting apparatus'is arranged in such a manner that while a-sub-' scriber operates his connecting ap aratus for the purpose of connecting himseii with another subscriber the main line connected to the'telephone apparatus of the first sub-.

scriber is broken, socas notto prevent the continued connection operation of the said subscriber. The break is made at the con-' tact-sprin s 57 58, attached-to the armature manner, as to be moved away during the connection operation from their contacts'55 and j 33 of the ocking electromagnet 11 in such a means are further provlded to signify a line connected for conversation to be busied. In the form of carrying out the invention illustrated' in the drawingsthe ar ature 37 of the cut-out electromagnet 12 c I 'es an insulated contact-Sp 61, having such a position that, 'whe the armature is attracted, said -spring. .61'bears u' on a contact 62, thereby c osin I a circuit ora test-battery 63, one

poleo which is connected'thro h a wire 64 with the contact-s ring 61, w ethe other 1 pole is connected, t ough a wire65, a resist-, ance =66 interposed between the electromagnets 9'and 1 0,and a wire 67, with the contact 62. When the armature 37 is attracted, a 1 current will thus flow'partly through wire 65, 'Iconversationand the long distance lineis connected b resistance 66,-wire3-,67-,' contact 62, contactspring 61, and-wire 64 back to the battery 7 line 1, switch 3, telephone-apparatus, switch 4, line 2, electroma et 10,- wire 67, contact 62, spr1ng61,'and "wire 64 back to-the battery- 63. As efore stated, the cut-out electroma at of a connecting apparatussaiy B after wil still hold its armature 37 attracte the connecting operation has been performed" through wire 65 electromagnet 9,

it substation II. 'If the shunt-circuit through-the telephone apparatus is brokenfor instance, at 3 or 4-a click will be' -hea-rd in the telephonemeeeiver announcing the desired substation to be busied, or an impe- I danc-coil68oan be interposed in-one line.

branch 2 between the switch i and the telephone apparatus, said coil being connected in .paralle with a key 6.9, cooperating with a contact 70 so that the coil :68 can be shortcircuited by depressing the key 69. On account of the varying resistance the shuntcircuit, due to alternately short-circuiting and cutting-in the impedance-coil 68, clicks will be heard in the telephonedeceiver when the desired substation is busied.

A great advantage of the arrangements described is that each separate conneoting apparatuscan be removed as a whole byloosening one or more screws and then be substi 'tuted by a new one without interfering with any connections for the other apparatus, due

V to the fact that the whole system of connectof subscribers, and when this number is increased the number of connecting apparatus is increased accordingly. 3 it may be explained that the magnets 9 and 10 are constructed, asindicatedin the drawings, as ordinary soils or solenoids with an iron core, and their armatures 22 and 23 are of soft iron, whereby they will be attract- -ed when the magnets are energized by either alternating or direct currents.

Having now described my in vention, what I claim as new, and desire to secure by Let ters' Patent, is- I 1. A double-wire telephone system with automatic exchange, comprising at the -sub-' stations two switches 3, 4, one included "each line branch, and contacts 5,6 for grounding the line branches through the said switches and further comprising two electromagnets 9, 10 interposed in series between the line branches, a battery 27 supplying current for establishing the desired con-noe tions, one pole of said battery being grounded, the other conneotible with the adjacent ends of the eleetromagnets =9, 10, means through which such connection may be made,

armatures 22 and 23 actuated by the electromagnets, -a feeding-pawl 28 attached to the armature 22 of one eleetromagnet (called the con-necting-electromagnet), a movable part 29 engaged by the feeding pawl 28 in such a manner that,-When the connecting-electromagnet 9 is deprived of current and its armature 22 is retracted, the said movable part 29 is fed forward, connecting-springs 1'5, 16 carriedfiby the said movable part, each spring being connected with one line branch of the corresponding substation, connectingsvi-res corresponding to the different substations, and a pawl'30 attached to the armature 23 of the other eleetromagnet (called the disconnecting-electroma net) in such a manner that, when the sai electromagnet 10 is-supplied with current and its armature 23 is attracted, said pawl engages the movable part 29 to prevent it from return movement, substantially-asdescri-bed.

2. A doublewire-telephone system with automatic exchan e, comprising at the sub stations two switc es 3, 4, one included in each line branch, and contacts '5,-.6for grounding the line branches through the said switches, and further coincprising two electromagnets-9, 10 inter-pose in series between the ine branches, a battery 27 supplying current for establishing the desired connections, one pole of said battery being grounded, the other connectible with the adjacent ends of the eiectromagnets -9 and 10, means through which-such connection may be made, armatures 22 23 actuated by the electromagnets, a feeding pawl 28 attached to the armature 22 of one-electromagnet(the connecting-electroma net -a movable part 2S9 engaged by the fee ing-paw-l 28 in such a manner that, when the connecting-electroinagnet 9 is deprived of current and its armature 22 is retracted, the said movable part is ted forward into its successive positimasto establish the desired connection, connecting-enrjin s i5, :16 carried by thesaid movable part, eac' spring being connected with one l ne branchof the corresponding substation, eonneetingavires corresponding to the difierent substations, a pawl 30 attached to the armature 23 of the other ieleotromagnet (the disconnecting-clos tromagnet) in such a manner that, *when the said electromagnet 10 is supplied with current and its armature 23 is attracted, said pawl engages the movable part 29 to prevent "it from return movement, and resistances '35, -36interposedin the conductors 13, 14 between the substations, substantially as described.

3. A double-wire telephonesystem with automatic exchan e, comprising at the substations two switces 3, 4, one included in eech'line branch, and contacts 5, 6 forground. ing the line branches through the said switches, and further comprising two electromagnets 9, L0 interposed in series between the line branches, one of said magnets 9 serving to establish the desired connections and the other 10 for discoimection, -a battery 27 one pole of which is grounded, the other connectible with the adjacent ends of the electromagnets 9, 10, means through which such connection may be made, armatures 22 and actuated by the electrom-agnets, a movable part 29 adapted to be fed forward in successive positions by the armature 22 of the eonnec-tmg-electromagnet 9 whenever the latter is deprived of current and itsarmature 1s retracted, connecting-springs 15, 16 car ried by thesaid movable part, each s rin be ingconnected with one line bra'ncli of the' correspondingsubstation, connecting-wires 5 'correspondin' .to the diflerent substations, l mealis contro led by the armature. '23 of the disconnectingelectromagnet to prevent the movable part 29 from return movement during the connection operation, and a lock-' 1,o"ing -el ectromagnet 11 inter osedbetween the 7 battery 27 at one side and t e connecting and disconnecting electromagnets at the other side,-the 'armature 33 of the locking-electromagnet being arranged to normally-lock the 1 5 armature 22 of the connecting-electromagnet 9 in position until the said locking-electroma net is supplied with current, substantialyas described. v

4. A double-wire telephone system with automatic exchan c, comprising at the substations tw'o'switc es 3, 4, one included in each line branch, and contacts 5, 6, for grounding the line branches through the said switches, and further comprising two electromagnets 9,- 10 interposed in series between the line branches, one of said inagn'ets 9 serving to establish the desired connections and the other 10 for disconnection, a battery 27 one pole of which is groundedfthe other con- 0 nectible with theadjacent en ds of the electromagnets 9' and 1 0, means through which such connection may be made, armatures' 22 and 23 actuated byv the electromagnets, a movable part 29 adapted to be fed forward in 5 successive positions bythe' armature22 of the connecting-electromagnet 9. whenever the latter is deprivedof current and its armature is retracted, means controlled by the armature 230f the disconnecting-electromagnet 4o 10 to prevent the movable part 29 from return movement during the connection opera- "tion, a locking-electromagnet 11 interposed between the battery 27 at'one side and'fthe connectihg'and disconnecting electromagnets- 9and l0 atthe other side, the armature 33 of the lockin -electromagnet beingsarrangedto 3 'normally ock the armature -22 of the'connecting-electromagnet 9 untilt'he said lock ing-ele otromagnet is supplied with-current, av cut-out electroma et 12 interposed between the battery 27 an the lockingselectromagnet' 1 1-, said cutsout electromagnet being carried f by the. movable part 29, connectin -springs 1 15, 16 carried bythe armature 37" o the said cut-out" electromagnet 12, each spring being connected'with. one :lin'ejbranch ofthe. corresponding substation, and connectingsw'ires corresponding "to the different substations,

substantiall as described. 6o 5."A-dou la -wire telephone system with automatic exchan e, comprising at thesub station two switc es '3, 4, one included-in each line" branch, and contacts 5, 6 -for grounding the line branches through thesaid' switches, and further comprising two electromagnets 9, .1 0 interposed in series between the ine branches, one of said magnets 9 servin-g to establish the desired connection and thelother 10 for disconnection, a battery 27 one pole of which rounded, the other; con.- nectible with the a jacent ends of the elect'romagnets'Q and 10, means through which such connection may be made, armatures 22 1 and 23 actuated by the electromagnets, a movable part- 29 adapted to be fed forward in successivc'positions by the armature 22 of the connecting electromagnet 9 whenever the latter'is deprived ofcurrent and it's armature 'i's-retracted, means controlled by the armature 23 of the disconnecting-e1ectromagnet 10- to prevent the movable part 29 from return movement'during the connection oper ation, a locking-electromagnet 11 interposed responding to-the different substations, cut- 7 out wires 121, 122,123 &c. extending along the different connecting apparatus, a cut-out spring 38, 40 traveling over one after the other'of the said cut-out wires, said spring being attached to the armature 37 of the cut-out electromagnet i2, contacts 41, 42 arranged in proximity to the cut-out sp'ring 38, 40 n such a manner that the said s ring is caused to make contact withone or t e other of the saidlcontacts 41, 42 according as the arma.--

tut-e37 {of the cut-out electromagnet' is at- 'traoted, for not, one contact (the reposin contact 41)bei11gconnected with one pole o t a cut-out battery 45 while thefother contact through the cut-out electromagnet j with the "other poleof'ithe saidbattery'45, Gut-out springs 49, '50," one ,49 connected with the first pole of the cutout ,batteryAS and the. 2; other 50 connected withthe butout wirev of the corresponding connecting and means "for? keep" 7 the sa springs 49, 50-apart unti the connecting ap- -'paratus is a paratus, id

cut-out put action, substantiallyasde automaticexchangefcomprising at the sub? I stations; two'swit'ches 3., 4, one included in each" ]ine branch,' =and' contacts 5, 6 for grounding the 'linebranche'lathrough the said switehes, and further comprising twoelectromagnets 9, 1'0 interposed in series between.

the line branches, one of said 'rnagnets 9 serving to establish the desired connections and the other .10 for disconnection,- a battery-.27

onepole of'which is grounded, the other connectible with the adjacent ends of the electromagnets 9 andlO, means through which such connection may be made,armatures 22 and 23 actuated by the 'electromagnets, a movable part 29' adapted to be fed forward in successive positions by the armature 22 of the connecting-electromagnet '9' whenever the latter is deprived of current and its arm-ature is retracted, means controlled by the armature 23 of the disconnecting-elect-romagnet to prevent the movable part 29 from return-movement during the connection operthe battery 27 and the locking-'electromagnet 11, said cut-out electromagnet being carried by the movable part- 29, connectin -springs 15, 16,0arried by the armature 37 0 the said cut-out electromagnet 12, each spring being connected with one line branch of the correspending substation, connecting-wires correautomatic exchan e, comprising at the'subsponding .to the different substations, 'cut-' outwires 121', 122, 123 &c. extending along ation, a locking-electromagnet 11 interposed r the different connecting apparatus, a cut-out spring '38, 40 traveling over one after the other of the said cut-out wires, said spring being attached to the armature 37 of the cutout electromagneti12, contacts-41, 42 arranged in proximity to the cut-out spring 38,

40 in such a manner that the said spring is caused. to make contact with one or the other of the said contacts 41, 42 according as the armature 37 of' the cut-out electromagnet is attracted,'or not, one contact (the reposing contact 41) being connected with one pole of;

a cut out battery 45' while the other contact (the working contact 42) is connected. through the cut-out electromagnet with the other pole of the-said battery 45, cut-out springs 49, 50, .one 49-connected with the first pole of the cut-out battery 45 and the other 50 connected With the cut-out wire of the corresponding connecting apparatus, means for keepin the said-cut-out springs 49, 50 apart unti the connecting apparatus is putin action, and a special connecting ap aratus A for a long-distance line, substantia ly as described, 7. A double-Wire telephone system with stations two switc cs3, 4, one included in each line :branch, and contacts 5, 6 for grounding the line branches throughthe said switches, and further comprising two electromagnets 9, 1O interposed in series between the line branches, one of said magnets 9 serving to establish the desired connections and the other 1-0 for disconnection, a battery 27 one pole of which is grounded, the other connectible with the adjacent ends of the'electromagnets 9 and 10, means through which such connection may be made, armatures '22 and 23 actuated by the electromagnets, a

movable part 29 adapted to be fed forward in successive positions by the armature 22 of the connecting electromagnet 9 whenever the latter is deprived of current. and its armature is retracted, means controlled by the .armature- 23 of the disconnecting-electromagnet 10 to prevent the movable part 29 from return movement during the connectionoperation, a lockin -electromagnet 11 interposed between the mattery 27 at one side and the connecting and disconnecting electromagnets 9 and ,10 at the other side,- the armature 33 of the locking-electromagnet being arranged to normally lock the armature 22 of the connecting-electromagnet 9 until the said locking-electromagnet is supplied with current, a cut-out electromagnet 12 interposed between the battery 27 and the locking-electromagnet 11, said cut-out electromagnet being carried by. the movable part 29, connecting-springs 15,16 carried by the armature 37 of the said cut-out electromagnet 12, each spring being connected with one line branch of the corresponding substation, connecting-wires corresponding to the different substations, cut-out wires 121', 122, 123 &c. extending along the different connecting apparatus, a cut-out spring 38, 40 traveling over one after the other of the said cut-outwires, said spring being attached 'to the armature 37 of the cut-out electromagnet 12, contacts 41 42 arranged in proximity to the cut-out spring 38, 40 in such amanner that the said spring is caused to make contact with one or the other of the said contacts 41, 42 according-as the armature 37 of the cut-out electromagnet is attracted, or not, one contact (the reposing contact 41) being connected with one pole of a cut-out battery 45 While the other contact (the working contact 42) is connected through the cut-out electromagnet With the other .pole of the said battery 45, cut-out springs 49, 50, one 49 connected with the first pole of the cut-out battery 45 and the other 50 connected with the cut-out wire of the corresponding connecting apparatus, means for keeping the said cut-out springs 49, 50 apart until the connecting apparatus is put' in action, and the s ecial connecting apparatus A for a longistance line substantially as described.

8. A double-wire telephone system with ICC automatic exchange, comprising at the substations two switches 3, 4, one included in each line branch, and contacts 5, 6for grounding the line branches through the said switches, and further comprising .two

electromagnets 9, 10 interposed in series between, the line branches, one of said magnets 9 serving to establish the desired connections connectible with the adjacent ends of the ele'ctromagnets 9' and 10, means through which such connection may be made, arma- I0 tures 22 and 23 actuated by the electromagnets, a movable part 29 adapted to be fed forward in successive positions by the armature 22 of the connecting-electromagnet 9 whenever the latter is (leprived'of current, -15 and 1ts armature isretracted, means controlled by the armature-23 of the disconnecting-ele'ctromagnet 10 to prevent the movable part 29 from return movement during .the connection operation, a lockin -electr0mag- 20 net 11 interposed between the battery 27 at one side and the connecting and disconnecting electromagnets 9 and-10 at the other side, -the armature 33 of thelocking-electromagnet being arranged to normally look the ar- 25 mature 22 of the connecting-electromagnet with one linebranc A substation, connecting-wires corresponding 5 9 until the said locking-electromagnet is sup plied with current, a cut-out electromagnet 12 interposed between the battery 27 and the locking-electromagnet 11, said cut-out electromagnet beirg carried-by the movable 0] part 29, connecting-springs 15, 16 carried by the armature 37 of the said cut-out electromagnet 12, each pring being connected I of the corresponding to the different substations, and a circuit comprisin a test-battery 63, a resistance 66 interpose between the connecting-electromagnet 9 and the disbonnecting-lectromag: net 10, a stationary contact 62, and a e06 4o erating movablecontact 61 carried by t e armature 37 of the cut-out electromagnet 12, substantially as described.

I In witness whereof- I have hereunto si ned my name in the presence of two subscri ing 5 witnesses.

M GOTTHILF ANSGARIUS BETULANDER.

r Witnesses:

ERNST SVAN vIsT, AUG. SOBENSEN. v 

